Method of applying curved leg elastics using rotating disks

ABSTRACT

A method of applying curved leg elastics to absorbent garments involves stretching and wrapping a pair of elastic ribbons about a first curved surface of a pair of disks. A portion of each of the elastic ribbons folds onto a second surface of each of the disks. The disks are rotated about a point off-center from a center point of the disks. The portions of the elastic ribbons on the second surfaces of the disks are rotated onto a substrate and bonded to the substrate in their stretched positions on the disks, thereby forming finished seams. The resulting absorbent garments have gasket-like leg openings with improved comfort and aesthetic appeal.

FIELD OF THE INVENTION

This invention is directed to a method of producing fully encircling,curved leg elastics. The method involves placing a pair of elasticribbons on a pair of disks that rotate off-center to provide a cammingfunction, and subsequently applying the elastic ribbons to a substrate.

BACKGROUND OF THE INVENTION

Pant-like absorbent garments, such as adult incontinence wear, as wellas infant and children's diapers, swim wear and training pants,typically include a pair of leg openings having an elastic portionaround each leg opening. The elastic portions are intended to fit snuglyaround a wearer's legs to prevent leakage from the garment.

Various technologies are known for applying leg elastics to sucharticles. For example, one technology involves bonding a continuous loopto a substrate. However, producing a supply of continuous loops ofelastic strands is more costly and cumbersome than providing a supply ofa continuous length of elastic ribbons.

Articles which incorporate conventional elasticized margins andconventional barrier flap configurations at their leg openings have,however, exhibited various shortcomings. For example, it has beendifficult to avoid pressure-induced marking of the wearer's skin anddifficult to maintain the desired gasketing of the leg openings when thearticles are being worn. Even when the leg openings are fitted with anelastomeric material or otherwise elasticized, it has been difficult tomaintain contact between the leg opening and the wearer's body foreffective containment of urine and feces. As a result, there has been acontinued need for improved containment structures at the leg regions ofabsorbent articles.

There is a need or desire for a process for making comfortable,gasket-like leg elastics that are aesthetically pleasing and can beapplied in a high-speed application.

SUMMARY OF THE INVENTION

The present invention is directed to a method of applying curved legelastics to pant-like absorbent garments using disks that rotateoff-center. Apparatus that can be used for carrying out the inventionincludes at least one pair of rotating disks, a cutting device, and abonding device. The rotating disks have a curved surface around which anelastic ribbon is stretched. The result is a comfortable, flexible,aesthetically pleasing leg opening. Furthermore, the resulting legopening is form-fitting and acts like a gasket.

In carrying out the invention, each elastic ribbon of a pair of elasticribbons is guided onto one of the disks. The elastic ribbon is guidedonto the pucks such that a portion of the elastic ribbon overhangs theedge of the first curved surface. Tension in the elastic ribbon causesthe overhanging portion to fold over onto an adjacent, second curvedsurface of the puck. The disk is juxtaposed to a substrate to which theelastic ribbon will be applied. The disk rotates about a pointsignificantly off-center from a center of the disk, thereby providing anoscillating motion towards the substrate. The second portion of theelastic ribbon is bonded to the substrate.

The elastic ribbons are cut into discrete lengths prior to carrying outthe method of the invention by using a slip cut applicator. The elasticribbon is fed onto an anvil of a slip cut unit. The anvil is suitablywide enough to support a fall width of the elastic ribbon to enable easycutting with a knife portion of the slip cut unit. The cut segment ofelastic ribbon is then transferred to the disk and held in place with avacuum.

The method of the invention can be used in high-speed applications,namely applications running at linear speeds of 600 feet per minute orgreater. The substrate may be stretchable or extensible, therebyproviding great flexibility and enabling the elastic ribbons to beapplied at low tension. Furthermore, stretchability and/or extensibilityof the substrate provide for a larger leg fit range.

The resulting product is an absorbent garment having a comfortable,aesthetically pleasing, finished look about the leg openings. Thismethod can also be used to apply curved standing leg cuffs and/or curvedleak guard flaps.

With the foregoing in mind, it is a feature and advantage of theinvention to provide a method of applying curved leg elastics to anabsorbent garment.

It is another feature and advantage of the invention to provide a methodof applying leg elastics to an absorbent garment resulting ingasket-like leg openings.

It is yet another feature and advantage of the invention to provide amethod of applying leg elastics to an absorbent garment resulting inform-fitting leg openings.

It is a further feature and advantage of the invention to provide amethod of applying leg elastics to an absorbent garment resulting incomfortable and aesthetically pleasing leg openings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of an absorbent garment;

FIG. 2 is a top view of an apparatus and substrate, including two slipcut applicators and two rotating disks that rotate off-center, used toproduce curved leg elastics;

FIG. 3 is a front view of the apparatus in FIG. 2;

FIG. 4 is a side view of the apparatus of FIGS. 2 and 3;

FIG. 5 is a perspective view of one of the disks of the apparatus shownin FIGS. 2, 3 and 4;

FIG. 6 is another perspective view of the disk in FIG. 5;

FIG. 7 is a top view of a substrate, showing a pair of curved legelastics bonded to the substrate;

FIG. 8 is a front view of an absorbent garment showing how the legelastics are bonded to the substrate;

FIG. 9 is a front view of an absorbent garment showing leg elasticmembers with rolled edges; and

FIG. 10 is a plan view of the absorbent garment of FIG. 1 in a partiallydisassembled, stretched flat state, and showing the surface of thearticle that faces the wearer when the article is worn, and withportions cut away to show the underlying features.

DEFINITIONS

Within the context of this specification, each term or phrase below willinclude the following meaning or meanings.

“Bonded” refers to the joining, adhering, connecting, attaching, or thelike, of two elements. Two elements will be considered to be bondedtogether when they are bonded directly to one another or indirectly toone another, such as when each is directly bonded to intermediateelements.

“Curved” refers to an opening, band, flap, surface, or edge, at least aportion of which is curved, i.e. has a radius of curvature and an arccovering at least 30°. Preferably, the opening, band, flap, surface, oredge is curved over at least 90°, more preferably at least 180°.

“Disposable” refers to articles which are designed to be discarded aftera limited use rather than being laundered or otherwise restored forreuse.

“Elastic,” “elasticized” and “elasticity” mean that property of amaterial or composite by virtue of which it tends to recover itsoriginal size and shape after removal of a force causing a deformation.

“Elastomeric” refers to a material or composite which can be elongatedby at least 25 percent of its relaxed length and which will recover,upon release of the applied force, at least 10 percent of itselongation. It is generally preferred that the elastomeric material orcomposite be capable of being elongated by at least 100 percent, morepreferably by at least 300 percent, of its relaxed length and recover,upon release of an applied force, at least 50 percent of its elongation.

“Extensible” refers to a material capable of being extended or protrudedin length or breadth.

“Film” refers to a thermoplastic film made using a film extrusion and/orfoaming process, such as a cast film or blown film extrusion process.The term includes apertured films, slit films, and other porous filmswhich constitute liquid transfer films, as well as films which do nottransfer liquid. The term also includes film-like materials that existas open-celled foams.

“Force” includes a physical influence exerted by one body on anotherwhich produces acceleration of bodies that are free to move anddeformation or separation of bodies that are not free to move.

“Hydrophilic” describes fibers or the surfaces of fibers which arewetted by the aqueous liquids in contact with the fibers. The degree ofwetting of the materials can, in turn, be described in terms of thecontact angles and the surface tensions of the liquids and materialsinvolved. Equipment and techniques suitable for measuring thewettability of particular fiber materials or blends of fiber materialscan be provided by a Cahn SFA-222 Surface Force Analyzer System, or asubstantially equivalent system. When measured with this system, fibershaving contact angles less than 90° are designated “wettable” orhydrophilic, while fibers having contact angles greater than 90° aredesignated “nonwettable” or hydrophobic.

“Layer” when used in the singular can have the dual meaning of a singleelement or a plurality of elements.

“Leg elastic” includes elastic bands, strands, ribbons, filaments,filament bunches and the like, which are adjacent to a garment openingthat receives a wearer's leg.

“Liquid impermeable,” when used in describing a layer or multi-layerlaminate, means that a liquid, such as urine, will not pass through thelayer or laminate, under ordinary use conditions, in a directiongenerally perpendicular to the plane of the layer or laminate at thepoint of liquid contact. Liquid, or urine, may spread or be transportedparallel to the plane of the liquid impermeable layer or laminate, butthis is not considered to be within the meaning of “liquid impermeable”when used herein.

“Liquid-permeable material” or “liquid water-permeable material” refersto a material present in one or more layers, such as a film, nonwovenfabric, or open-celled foam, which is porous, and which is waterpermeable due to the flow of water and other aqueous liquids through thepores. The pores in the film or foam, or spaces between fibers orfilaments in a nonwoven web, are large enough and frequent enough topermit leakage and flow of liquid water through the material.

“Longitudinal” and “transverse” have their customary meaning, asindicated by the longitudinal and transverse axes depicted in FIG. 11.The longitudinal axis lies in the plane of the article and is generallyparallel to a vertical plane that bisects a standing wearer into leftand right body halves when the article is worn. The transverse axis liesin the plane of the article generally perpendicular to the longitudinalaxis. The article as illustrated is longer in the longitudinal directionthan in the transverse direction.

“Meltblown fibers” means fibers formed by extruding a moltenthermoplastic material through a plurality of fine, usually circular,die capillaries as molten threads or filaments into converging highvelocity heated gas (e.g., air) streams which attenuate the filaments ofmolten thermoplastic material to reduce their diameter, which may be tomicrofiber diameter. Thereafter, the meltblown fibers are carried by thehigh velocity gas stream and are deposited on a collecting surface toform a web of randomly dispersed meltblown fibers. Such a process isdisclosed for example, in U.S. Pat. No. 3,849,241 to Butin et al.Meltblown fibers are microfibers which may be continuous ordiscontinuous, are generally smaller than about 0.6 denier, and aregenerally self bonding when deposited onto a collecting surface.Meltblown fibers used in the present invention are preferablysubstantially continuous in length.

“Member” when used in the singular can have the dual meaning of a singleelement or a plurality of elements.

“Nonwoven” and “nonwoven web” refer to materials and webs of materialwhich are formed without the aid of a textile weaving or knittingprocess.

“Operatively attached,” in reference to the attachment of an elasticmember to another element, means that the elastic member when attachedto or connected to the element, or treated with heat or chemicals, bystretching, or the like, gives the element elastic properties; and withreference to the attachment of a non-elastic member to another element,means that the member and element can be attached in any suitable mannerthat permits or allows them to perform the intended or describedfunction of the composite. The joining, attaching, connecting or thelike can be either directly, such as joining either member directly toan element, or can be indirectly by means of another member disposedbetween the first member and the first element, or can be such that thefirst member is mechanically trapped by adjacent bond points in thefirst element such that the first member causes the composite to exhibitcharacteristics of the first member.

“Polymers” include, but are not limited to, homopolymers, copolymers,such as, for example, block, graft, random and alternating copolymers,terpolymers, etc. and blends and modifications thereof. Furthermore,unless otherwise specifically limited, the term “polymer” shall includeall possible geometrical configurations of the material. Theseconfigurations include, but are not limited to isotactic, syndiotacticand atactic symmetries.

“Spunbonded fibers” refers to small diameter fibers which are formed byextruding molten thermoplastic material as filaments from a plurality offine capillaries of a spinnerette having a circular or otherconfiguration, with the diameter of the extruded filaments then beingrapidly reduced as by, for example, in U.S. Pat. No. 4,340,563 to Appelet al., and U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No.3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394 toKinney, U.S. Pat. No. 3,502,763 to Hartmann, U.S. Pat. No. 3,502,538 toPetersen, and U.S. Pat. No. 3,542,615 to Dobo et al., each of which isincorporated herein in its entirety by reference. Spunbond fibers arequenched and generally not tacky when they are deposited onto acollecting surface. Spunbond fibers are generally continuous and oftenhave average deniers larger than about 0.3, more particularly, betweenabout 0.6 and 10.

“Stretchable” means that a material can be stretched, without breaking,by at least 50% (to 150% of its initial (unstretched) length) in atleast one direction, suitably by at least 100% (to 200% of its initiallength), desirably by at least 150% (to at least 250% of its initiallength).

“Surface” includes any layer, film, woven, nonwoven, laminate,composite, or the like, whether pervious or impervious to air, gas,and/or liquids.

“Tension” includes a uniaxial force tending to cause the extension of abody or the balancing force within that body resisting the extension.

“Thermoplastic” describes a material that softens when exposed to heatand which substantially returns to a nonsoftened condition when cooledto room temperature.

These terms may be defined with additional language in the remainingportions of the specification.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The present invention is directed to a method of applying curved legelastics to pant-like absorbent garments. Curved leg elastics, inaccordance with the invention, are leg elastics that follow a curvedcontour of a leg opening. The present invention results in curved legelastics having an unbonded elastic portion spanning an entire length ofthe leg elastics and a bonded elastic portion also spanning an entirelength of the leg elastics. The unbonded portion and the bonded portionare both part of a solitary unit, or ribbon, of elastic. The bondedportion is a portion of the elastic ribbon that is bonded to asubstrate. The unbonded portion can extend away from the bonded portionat an angle, or can lie juxtaposed to the bonded portion via a foldalong the length of the elastic ribbon. The unbonded portion has greaterfreedom to respond to internal tension when the garment is in a relaxedstate than the bonded portion, attributable to the fact that the bondedportion is bonded to the substrate in a stretched state, thereby causingthe bonded portion to be restrained in movement by the substrate. Theresulting disproportionate freedom of movement along the length of theelastic ribbon causes a curvature of the elastic ribbon. In addition tothe curvature caused by the disproportionate freedom of movement, thebonded portion is bonded to the substrate along a periphery of a curvedcut-out in the substrate. The curved shape of the bonded portionincreases the curvature of the leg elastics.

The principles of the present invention can be incorporated into anysuitable disposable absorbent article. Examples of such suitablearticles include diapers, training pants, feminine hygiene products,incontinence products, other personal care or health care garments, orthe like. As used herein, the term “incontinence products” includesabsorbent underwear for children, absorbent garments for children oryoung adults with special needs such as autistic children or others withbladder/bowel control problems as a result of physical disabilities, aswell as absorbent garments for incontinent older adults. For ease ofexplanation, the description hereafter will be in terms of a child'straining pant. Furthermore, the principles of the present invention canbe used to apply leg elastics, as well as leak guard flaps or leg cuffs,to the leg openings of pant-like absorbent garments. For ease ofexplanation, the description hereafter will be in terms of leg elastics.

Referring to FIG. 1, a disposable absorbent article, such as a trainingpant 20, is illustrated in a fastened condition. Leg elastics 10 areused around leg openings 12 of the training pant 20 to create a gasketand to reduce or prevent leakage. The term “gasket” refers to a devicethat is used to block fluid leakage around the leg openings, between thegarment and legs of a wearer. A main chassis 14 defines the leg openings12 and a waist opening 13. When the leg elastics 10 are curved, as inthe present invention, the leg elastics 10 are more form-fitting thanstraight edge leg elastics. The term “straight edge leg elastics” refersto typical leg elastics that are attached to a substrate in a straightline. As a result, the leg openings 12 are gathered with low tension,since the leg openings 12 do not have to overcome forces from a mainchassis 14 as straight edge leg elastics must overcome. The low tensionand form-fit results in an absorbent garment 20 with increased comfort.Additionally, the curved leg elastics 10 have a finished seam 16 whereattached to the main chassis 14, resulting in an aesthetically pleasingappearance.

The leg elastics 10 are preferably curved about the full circumferenceof the leg openings 12, but may alternatively only partially encirclethe leg openings 12, thereby resulting in curved leg elastics that arenot fully encircling.

One example of apparatus 3 for carrying out the invention is showngenerally in FIGS. 2, 3 and 4. The apparatus 3 includes a pair of disks24 which rotate about an off-center pivot point 23. The off-center pivotpoint 23 is suitably significantly off-center with respect to a centerpoint 22 of each disk 24, suitably at least 0.5 centimeter off-center,more suitably at least 1 centimeter off-center, even more suitably atleast 2 centimeters off-center, most suitably at least 3 centimetersoff-center, depending on the size of the disks 24. The disks 24 rotatejuxtaposed to a substrate 40 to which the leg elastics 10 will bebonded. The disks 24 suitably have at least one curved surface 26. Thefirst curved surface 26 may have any of a wide range of degrees ofcurvature along its length, with optimal curvature conforming tocurvature about a wearer's leg. The disks 24 are suitably non-circular,and may be kidney-shaped or heart-shaped, for example. The non-circularshape of the disks 24 can create irregularly shaped patterns, so as tooptimize fit of the leg openings 12 about a wearer's legs.

A disk 24 used in the invention is shown separately in FIGS. 5 and 6.The disk 24 has the first curved surface 26, as mentioned above, as wellas a second surface 28, with an edge 30 separating the first curvedsurface 26 and the second surface 28. The second surface 28 can have atexture or pattern on it to create a desired bonding pattern where theelastic will attach to the substrate. FIGS. 5 and 6 also show atensioned elastic ribbon 10 wrapped about the first curved surface 26 ofthe disk 24, as explained below.

The disks 24 each rotate about the off-center pivot point 23 in adirection complementary to the machine direction movement of thesubstrate 40. The machine direction is indicated by the arrow 47 inFIGS. 2 and 4. The machine direction in FIG. 3 is out of the paper.Guide rolls 36 are located in close proximity to each of the disks 24,but not necessarily in close proximity to one another (FIG. 2). Theelastic ribbons 10 used in the method of the invention are continuouslengths of elastic ribbon cut into discrete pieces by a cutting device34. As shown in FIG. 2, cutting devices 34 may also be used to transferthe discrete elastic pieces onto the disks 24. The cutting device 34 issuitably a slip cut applicator having an anvil 33 wide enough to supporta full width of the elastic ribbon 10, thereby enabling easy cuttingwith a knife portion 35 of the slip cut unit 34. A bonding device 32,such as an ultrasonic bonder, is also located in close proximity to eachof the disks 24, and may be located below the substrate 40, as shown inFIGS. 3 and 4. The disks 24 can either rotate onto the substrate 40 withsufficient pressure for the bonding process or, alternatively, thebonding devices 32 can exert force upward to carry out the bondingprocess.

In carrying out the invention, as shown in FIG. 2, the elastic ribbons10 are guided onto the anvils 33 of the slip cut applicators 34. Avacuum within the anvils 33 is used to hold the elastic ribbons 10 inplace on the anvils 33 after the ribbons 10 are cut by the cuttingdevice 34. Examples of other suitable cutting devices 34, in addition toslip cut applicators, include mechanical pinch cut-off knives, and hotknives or other cutting means well known in the art. As the anvils 33are rotated past the disks 24, the elastic ribbons 10 are transferred tothe first curved surfaces 26 of the disks 24. A vacuum within the disks24 is used to hold the elastic ribbons 10 in place on the disks 24.Alternatively or additionally, the disks 24 can have a nonslip textureon at least part of the first curved surfaces 26 and on at least part ofthe adjacent second surfaces 28 to hold the elastic ribbons 10 in place.The elastic ribbons 10 are transferred onto the first curved surfaces 26of the disks 24 such that a first portion 38 of the elastic ribbons 10is placed on the first curved surfaces 26 of the disks 24 while a secondportion 39 of the elastic ribbons 10 overhangs the edge 30 of the firstcurved surface 26. Tension in the elastic ribbons 10 and the curvatureof the first surface 26 cause the second portion 39 of the elasticribbons 10 to fold onto the adjacent second surfaces 28 of the disks 24.The elastic ribbons 10 are preferably stretched to at least 125%, morepreferably at least 150%, of their initial (unstretched) length as theyare wrapped about the first curved surface 26 of the disk 24. Thecutting device 34 is not necessarily directly mounted to the disk 24,but is mounted at least in close proximity to the disk 24.

The disks 24 are rotated toward the substrate 40 about the off-centerpivot points 23 as indicated by the arrows 54 in FIG. 2. The secondportion 39 of the elastic ribbon 10 on the second surface 28 of the disk24 remains substantially parallel to the substrate 40 throughout theprocess. The disks 24 rotate the second portions 39 of the elasticribbons 10 onto the substrate 40, and the second portions 39 are thenbonded to the substrate 40 in a machine direction. As the elasticribbons 10 are bonded to the substrate 40, the disks 24 continue torotate 360 degrees back to their initial position.

The substrate 40 is typically a liner 42 or an outer cover 44 of theabsorbent garment 20 (FIG. 1). As shown in FIGS. 2 and 8, the substrate40 preferably includes corresponding curved cut-outs along paralleledges 46 of the substrate 40. The term “curved cut-out” refers to anycut-out having a curved edge, which may include a single material thatis cut to form a cut-out or a plurality of materials that are bondedtogether to define a cut-out shape. The second portions 39 of theelastic ribbons 10 are bonded to the substrate 40 along an edge 56adjacent each of the curved cut-outs. The first portions 38 of theelastic ribbons 10 project upward from the substrate 40 and serve asgaskets during later use of the garment 20, as explained below.

The substrate 40 can be a continuous length, as shown in FIGS. 2 and 3,in which case the substrate 40 is cut into individual pieces for eachgarment 20 subsequent to the application of the elastic ribbons 10.Alternatively, the substrate 40 can be fed through the apparatus 3 inthe form of individual pieces for each garment 20, similar to the shapeof the substrate 40 in FIG. 8. The substrate 40 is preferablystretchable and/or extensible, thereby providing great flexibility,enabling the elastic ribbons 10 to be applied at low tension, andenabling a wide leg fit range.

FIG. 9 is a front view of an absorbent garment 20 with a pair of curvedleg elastics 10 bonded to the substrate 40, in this case, the outercover 44. FIG. 10 is a front view of an absorbent garment 20 showing thecurved leg elastics 10 with rolled edges 58. The rolled edges 58 providegreater strength and reinforcement around the leg openings 12, inaddition to an even more finished look. The rolled edges 58 can containa strand of elastic to provide an even more effective gasket. Aresulting seam 16 (see also FIGS. 1 and 9) joining the leg elastics 10and the substrate 40 has a finished appearance since edges of thesubstrate 40 and the second portion 39 of the leg elastics 10 are bothhidden from view on one side of the seam 16.

The second portions 39 of the elastic ribbons 10 can be bonded to thesubstrate 40 by ultrasonic bonding, as mentioned, or a variety of othertechniques including adhesive bonding, thermal bonding, stitch bondingor other conventional techniques. Suitable adhesives include sprayadhesives, hot melt adhesives, self-adhering elastomeric materials andthe like. Each suitable bonding technique is strong enough to separatethe elastic ribbons 10 from the vacuum in the disks 24, oralternatively, from the nonslip texture of the disks 24. As a furtheralternative, the vacuum itself can be released, thereby releasing theelastic ribbons 10 from the disks 24.

Once the elastic ribbons 10 have been bonded to the substrate 40, edges50 and 51 can be joined to edges 52 and 53, respectively, shown in FIG.8, to form the garments 20 shown in FIGS. 1 and 9. Once the garment 20is formed, the first portions 38 of the elastic ribbons 10 can projectupward from the garment surface. During use, the first portions 38 ofthe elastic ribbons 10 firmly engage the wearer's skin, thereby servingas gaskets to reduce or prevent leakage through the openings of thegarment 20.

The method of the invention can be used in high-speed applications,namely applications running at linear speeds of 600 feet per minute orgreater.

Referring to FIG. 11, the absorbent garment 20 of FIG. 1 is shown in apartially disassembled, stretched flat state, showing a surface whichfaces the wearer when the garment is worn. In addition to defining theleg openings 12 and the waist opening 13 (FIG. 1), the absorbent chassis14 also defines a pair of transversely opposed side edges 136 and a pairof longitudinally opposed waist edges, which are designated front waistedge 138 and back waist edge 139. The chassis 14 also includes asomewhat rectangular composite structure 133, a pair of transverselyopposed front side panels 134, and a pair of transversely opposed backside panels 234. The composite structure 133 and side panels 134 and 234may be integrally formed, as shown in FIG. 8, or may include two or moreseparate elements, as shown in FIGS. 1 and 11.

The illustrated composite structure 133 includes an outer cover 44, abody side liner 42 which is connected to the outer cover in a superposedrelation, and an absorbent assembly 144 which is located between theouter cover 44 and the body side liner 42. The rectangular compositestructure 133 has opposite linear end edges 145 that form portions ofthe front and back waist edges 138 and 139, and opposite linear, orcurvilinear, side edges 147 that form portions of the side edges 136 ofthe absorbent chassis 14. Leg openings 12 (FIG. 1) are generally definedby portions of the transversely opposed side edges 136. For reference,arrows 48 and 49 depicting the orientation of the longitudinal axis andthe transverse axis, respectively, of the training pant 20 areillustrated in FIG. 11.

The liquid permeable body side liner 42 is illustrated as overlying theouter cover 44 and absorbent assembly 144 (FIG. 11), and may but neednot have the same dimensions as the outer cover 44. The body side liner42 is desirably compliant, soft feeling, and non-irritating to thechild's skin. Further, the body side liner 42 can be less hydrophilicthan the absorbent assembly 144, to present a relatively dry surface tothe wearer and permit liquid to readily penetrate through its thickness.

The absorbent assembly 144 (FIG. 11) is positioned between the outercover 44 and the body side liner 42, which components can be joinedtogether by any suitable means, such as adhesives, as is well known inthe art. The absorbent assembly 144 can be any structure which isgenerally compressible, conformable, non-irritating to the child's skin,and capable of absorbing and retaining liquids and certain body wastes.The absorbent assembly 144 can be manufactured in a wide variety ofsizes and shapes, and from a wide variety of liquid absorbent materialscommonly used in the art. For example, the absorbent assembly 144 cansuitably include a matrix of hydrophilic fibers, such as a web ofcellulosic fluff, mixed with particles of a high-absorbency materialcommonly known as superabsorbent material. In a particular embodiment,the absorbent assembly 144 includes a matrix of cellulosic fluff, suchas wood pulp fluff, and superabsorbent hydrogel-forming particles. Thewood pulp fluff can be exchanged with synthetic, polymeric, meltblownfibers or with a combination of meltblown fibers and natural fibers. Thesuperabsorbent particles can be substantially homogeneously mixed withthe hydrophilic fibers or can be nonuniformly mixed. The fluff andsuperabsorbent particles can also be selectively placed into desiredzones of the absorbent assembly 144 to better contain and absorb bodyexudates. The concentration of the superabsorbent particles can alsovary through the thickness of the absorbent assembly 144. Alternatively,the absorbent assembly 144 can include a laminate of fibrous webs andsuperabsorbent material or other suitable means of maintaining asuperabsorbent material in a localized area.

Suitable superabsorbent materials can be selected from natural,synthetic, and modified natural polymers and materials. Thesuperabsorbent materials can be inorganic materials, such as silicagels, or organic compounds, such as crosslinked polymers. Suitablesuperabsorbent materials are available from various commercial vendors,such as Dow Chemical Company located in Midland, Mich., U.S.A., andStockhausen GmbH & Co. KG, D-47805 Krefeld, Federal Republic of Germany.Typically, a superabsorbent material is capable of absorbing at leastabout times its weight in water, and desirably is capable of absorbingmore than about 25 times its weight in water.

In one embodiment, the absorbent assembly 144 is generally rectangularin shape, and includes a blend of wood pulp fluff and superabsorbentmaterial. One preferred type of fluff is identified with the tradedesignation CR1654, available from U.S. Alliance, Childersburg, Ala.,U.S.A., and is a bleached, highly absorbent sulfate wood pulp containingprimarily soft wood fibers. As a general rule, the superabsorbentmaterial is present in the absorbent assembly 144 in an amount of fromabout 0 to about 90 weight percent based on total weight of theabsorbent assembly. The absorbent assembly 144 suitably has a densitywithin the range of about 0.10 to about 0.35 grams per cubic centimeter.The absorbent assembly 144 may or may not be wrapped or encompassed by asuitable tissue wrap that maintains the integrity and/or shape of theabsorbent assembly.

The absorbent chassis 14 can also incorporate other materials that aredesigned primarily to receive, temporarily store, and/or transportliquid along the mutually facing surface with the absorbent assembly144, thereby maximizing the absorbent capacity of the absorbentassembly. One suitable material is referred to as a surge layer (notshown) and includes a material having a basis weight of about 50 gramsper square meter, and including a through-air-bonded-carded web of ahomogenous blend of 60 percent 3 denier bicomponent fiber including apolyester core/polyethylene sheath, commercially available from BASFCorporation, and 40 percent 6 denier polyester fiber, commerciallyavailable from Hoechst Celanese Corporation, in Portsmouth, Va., U.S.A.

A wide variety of elastic materials may be used for the leg elastics 10.As is well known to those skilled in the art, suitable elastic materialsinclude sheets, strands or ribbons of natural rubber, synthetic rubber,or thermoplastic elastomeric polymers. The elastic materials can bestretched and adhered to a substrate, adhered to a gathered substrate,or adhered to a substrate and then elasticized or shrunk, for examplewith the application of heat; such that elastic constrictive forces areimparted to the substrate. In one particular embodiment, for example,the leg elastics 10 include a plurality of dry-spun coalescedmultifilament spandex elastomeric threads sold under the trade nameLYCRA® and available from E.I. DuPont de Nemours and Company,Wilmington, Del., U.S.A.

Each of the leg elastics 10 preferably has a width of about 0.5 inch(1.27 cm) to about 5 inches (12.7 cm), more preferably about 1 inch(2.54 cm) to about 4 inches (10.16 cm), most preferably about 1.5 inches(3.81 cm) to about 2.5 inches (6.35 cm). Second portions 39 of the legelastics 10 preferably have a width of about 0.25 inch (0.635 cm) toabout 4 inches (10.16 cm), more preferably about 0.5 inch (1.27 cm) toabout 3 inches (7.62 cm), most preferably about 1 inch (2.54 cm) toabout 2 inches (5.08 cm). The length of the leg elastics 10 once cut bythe cutting device 34 should substantially cover a circumference of theleg opening 12. Depending on the garment size, the leg elastics 10 mayhave a length of at least about 4 inches, preferably at least about 8inches, more preferably at least about 12 inches. Of course, the lengthsare shorter if the leg elastics 10 are not intended to fully encircle awearer's legs. Furthermore, each of the leg elastics 10 preferably haselongation of 25-350%, more preferably about 30-260%, most preferablyabout 35-200%.

The substrate 40 is preferably the outer cover 44 and desirably includesa material that is substantially liquid impermeable, and can be elastic,stretchable or nonstretchable. The outer cover 44 can be a single layerof liquid impermeable material, but desirably includes a multi-layeredlaminate structure in which at least one of the layers is liquidimpermeable. For instance, the outer cover 44 can include a liquidpermeable outer layer and a liquid impermeable inner layer that aresuitably joined together, such as by a laminate adhesive (not shown).Suitable laminate adhesives, which can be applied continuously orintermittently as beads, a spray, parallel swirls, or the like, can beobtained from Findley Adhesives, Inc., of Wauwatosa, Wis., U.S.A., orfrom National Starch and Chemical Company, Bridgewater, N.J., U.S.A. Theliquid permeable outer layer can be any suitable material and desirablyone that provides a generally cloth-like texture. One example of such amaterial is a 20 gsm (grams per square meter) spunbond polypropylenenonwoven web. The outer layer may also be made of those materials ofwhich liquid permeable bodyside liner 42 is made. While it is not anecessity for the outer layer to be liquid permeable, it is desired thatit provides a relatively cloth-like texture to the wearer.

The inner layer of the outer cover 44 can be both liquid and vaporimpermeable, or can be liquid impermeable and vapor permeable. The innerlayer is desirably manufactured from a thin plastic film, although otherflexible liquid impermeable materials may also be used. The inner layer,or the liquid impermeable outer cover 44 when a single layer, preventswaste material from wetting articles, such as bedsheets and clothing, aswell as the wearer and caregiver. A suitable liquid impermeable film foruse as a liquid impermeable inner layer, or a single layer liquidimpermeable outer cover 44, is a 0.02 millimeter polyethylene filmcommercially available from Huntsman Packaging of Newport News, Va.,U.S.A. If the outer cover 44 is a single layer of material, it can beembossed and/or matte finished to provide a more cloth-like appearance.As earlier mentioned, the liquid impermeable material can permit vaporsto escape from the interior of the disposable absorbent article, whilestill preventing liquids from passing through the outer cover 44. Asuitable “breathable” material is composed of a microporous polymer filmor a nonwoven fabric that has been coated or otherwise treated to imparta desired level of liquid impermeability. A suitable microporous film isa PMP-1 film material commercially available from Mitsui ToatsuChemicals, Inc., Tokyo, Japan, or an XKO-8044 polyolefin filmcommercially available from 3M Company, Minneapolis, Minn.

The bodyside liner 42 can be manufactured from a wide selection of webmaterials, such as synthetic fibers (for example, polyester orpolypropylene fibers), natural fibers (for example, wood or cottonfibers), a combination of natural and synthetic fibers, porous foams,reticulated foams, apertured plastic films, or the like. Various wovenand nonwoven fabrics can be used for the bodyside liner 42. For example,the bodyside liner can be composed of a meltblown or spunbonded web ofpolyolefin fibers. The bodyside liner can also be a bonded-carded webcomposed of natural and/or synthetic fibers. The bodyside liner can becomposed of a substantially hydrophobic material, and the hydrophobicmaterial can, optionally, be treated with a surfactant or otherwiseprocessed to impart a desired level of wettability and hydrophilicity.For example, the material can be surface treated with about 0.28 weightpercent of a surfactant commercially available from the Rohm and HaasCo. under the trade designation Triton X-102. The surfactant can beapplied by any conventional means, such as spraying, printing, brushcoating or the like. The surfactant can be applied to the entirebodyside liner 42 or can be selectively applied to particular sectionsof the bodyside liner, such as the medial section along the longitudinalcenterline.

A suitable liquid permeable bodyside liner 42 is a nonwoven bicomponentweb having a basis weight of about 27 gsm. The nonwoven bicomponent canbe a spunbond bicomponent web, or a bonded carded bicomponent web.Suitable bicomponent staple fibers include a polyethylene/polypropylenebicomponent fiber available from CHISSO Corporation, Osaka, Japan. Inthis particular bicomponent fiber, the polypropylene forms the core andthe polyethylene forms the sheath of the fiber. Other fiber orientationsare possible, such as multi-lobe, side-by-side, end-to-end, or the like.While the outer cover 44 and bodyside liner 42 can include elastomericmaterials, it can be desirable in some embodiments for the compositestructure to be generally inelastic, where the outer cover, the bodysideliner and the absorbent assembly include materials that are generallynot elastomeric.

As noted previously, the illustrated training pant 20 can have front andback side panels 134 and 234 disposed on each side of the absorbentchassis 14 (FIGS. 1 and 11). These transversely opposed front sidepanels 134 and transversely opposed back side panels 234 can bepermanently bonded to the composite structure 133 of the absorbentchassis 14 and are releasably attached to one another by a fasteningsystem 80 (FIG. 1). More particularly, as shown best in FIG. 11, thefront side panels 134 can be permanently bonded to and extendtransversely beyond the linear side edges 147 of the composite structure133 along attachment lines 69, and the back side panels 234 can bepermanently bonded to and extend transversely beyond the linear sideedges of the composite structure along attachment lines 69. The sidepanels 134 and 234 may be attached using attachment means known to thoseskilled in the art such as adhesive, thermal or ultrasonic bonding. Theside panels 134 and 234 can also be formed as a portion of a componentof the composite structure 133, such as the outer cover 44 or the bodyside liner 42.

Each of the side panels 134 and 234 can include one or more individual,distinct pieces of material. In particular embodiments, for example,each side panel 134 and 234 can include first and second side panelportions that are joined at a seam, with at least one of the portionsincluding an elastomeric material (not shown). Still alternatively, eachindividual side panel 134 and 234 can include a single piece of materialwhich is folded over upon itself along an intermediate fold line (notshown).

The side panels 134 and 234 desirably include an elastic materialcapable of stretching in a direction generally parallel to thetransverse axis 49 of the training pant 20. In particular embodiments,the front and back side panels 134 and 234 may each include an interiorportion 78 disposed between a distal edge 68 and a respective front orback center panel 135 or 235. In the illustrated embodiment in FIG. 1,the interior portions 78 are disposed between the distal edges 68 andthe side edges 147 of the rectangular composite structure 133. Theelastic material of the side panels 134 can be disposed in the interiorportions 78 to render the side panels elastomeric in a directiongenerally parallel to the transverse axis 49. Most desirably, each sidepanel 134 is elastomeric from a waist end edge 72 to a leg end edge 70.More specifically, individual samples of side panel material, takenbetween the waist end edge 72 and the leg end edge 70 parallel to thetransverse axis 49 and having a length from the attachment line 69 tothe distal edge 68 and a width of about 2 centimeters, are allelastomeric.

Suitable elastic materials, as well as one described process ofincorporating elastic side panels into a training pant, are described inthe following U.S. Pat. No. 4,940,464 issued Jul. 10, 1990 to Van Gompelet al.; U.S. Pat. No. 5,224,405 issued Jul. 6, 1993 to Pohjola; U.S.Pat. No. 5,104,116 issued Apr. 14, 1992 to Pohjola; and U.S. Pat. No.5,046,272 issued Sep. 10, 1991 to Vogt et al.; all of which areincorporated herein by reference. In particular embodiments, the elasticmaterial includes a stretch-thermal laminate (STL), a neck-bondedlaminate (NBL), a reversibly necked laminate, or a stretch-bondedlaminate (SBL) material. Methods of making such materials are well knownto those skilled in the art and described in U.S. Pat. No. 4,663,220issued May 5, 1987 to Wisneski et al.; U.S. Pat. No. 5,226,992 issuedJul. 13, 1993 to Morman; and European Patent Application No. EP 0 217032 published on Apr. 8, 1987 in the names of Taylor et al.; all ofwhich are incorporated herein by reference. Alternatively, the sidepanel material may include other woven or nonwoven materials, such asthose described above as being suitable for the outer cover 44 or bodyside liner 42, or stretchable but inelastic materials.

The absorbent chassis 14 and the fastening system 80 together define arefastenable pant having a waist opening 13 and a pair of leg openings12 (FIG. 1). When the fastening system is engaged, it can be appreciatedthat the refastenable pant includes a pair of elastomeric front sidepanels 134 extending from the waist opening to each leg opening, a pairof elastomeric back side panels 234 extending from the waist opening toeach leg opening, a pair of refastenable seams 88 (FIG. 1) extendingfrom the waist opening to each leg opening and positioned between theelastomeric front and back side panels, an elastomeric front waistband154 positioned between the pair of elastomeric front side panels 134, anelastomeric back waistband 156 positioned between the pair ofelastomeric back side panels 234, and a pair of curved leg elastics 10which encircle each leg opening 12. Alternatively, instead ofrefastenable seams 88, the absorbent garment of the invention can havebonded side seams.

As described herein, the various components of the training pant 20 canbe integrally assembled together employing various types of suitableattachment means, such as adhesive, sonic and thermal bonds orcombinations thereof. The resulting product is an absorbent garment 20having a comfortable, gasket-like fit and an aesthetically pleasing,finished look about the leg openings 12. The gasket-like fit caneliminate a need for separately attached side flaps, thereby eliminatingadditional time and material costs. The pant-like absorbent garment 20can be sized and tailored for a wide variety of uses including, forexample, diapers, training pants, swimwear, adult incontinence garments,and the like. The curved leg elastics of the present invention can alsobe used for curved standing leg cuffs. Alternatively, leak guard flapscan be attached to an absorbent garment in the same manner as the legelastics are attached to an absorbent garment in the present invention.

It will be appreciated that details of the foregoing embodiments, givenfor purposes of illustration, are not to be construed as limiting thescope of this invention. Although only a few exemplary embodiments ofthis invention have been described in detail above, those skilled in theart will readily appreciate that many modifications are possible in theexemplary embodiments without materially departing from the novelteachings and advantages of this invention. Accordingly, all suchmodifications are intended to be included within the scope of thisinvention, which is defined in the following claims and all equivalentsthereto. Further, it is recognized that many embodiments may beconceived that do not achieve all of the advantages of some embodiments,particularly of the preferred embodiments, yet the absence of aparticular advantage shall not be construed to necessarily mean thatsuch an embodiment is outside the scope of the present invention.

We claim:
 1. A method of producing a curved leg elastic, comprising thesteps of: guiding an elastic ribbon onto at least a portion of aperiphery of a disk; rotating the disk about a point off-center from acenter point of the disk; and bonding a portion of the elastic ribbon tothe substrate.
 2. The method of claim 1, wherein the disk rotatesjuxtaposed to the substrate.
 3. The method of claim 1, wherein theoff-center point is at least 0.5 centimeter off-center from the centerpoint.
 4. The method of claim 1, wherein the off-center point is atleast 1 centimeter off-center from the center point.
 5. The method ofclaim 1, wherein the off-center point is at least 2 centimetersoff-center from the center point.
 6. The method of claim 1, wherein theoff-center point is at least 3 centimeters off-center from the centerpoint.
 7. The method of claim 1, wherein the disk is non-circular. 8.The method of claim I, wherein the disk is kidney-shaped.
 9. The methodof claim 1, further comprising the step of guiding a first portion ofthe elastic ribbon about at least a portion of the periphery of the diskalong a first curved surface, such that a second portion of the elasticribbon folds over an edge of the disk onto a second surface of the disk.10. The method of claim 9, further comprising the step of bonding thesecond portion of the elastic ribbon to the substrate.
 11. The method ofclaim 9, further comprising the step of ultrasonically bonding thesecond portion of the elastic ribbon to the substrate.
 12. The method ofclaim 1, further comprising the steps of guiding the elastic ribbon ontoa slip cut unit and cutting the elastic ribbon.
 13. The method of claim12, wherein a full width of the elastic ribbon is supported on a firstsurface of the slip cut unit.
 14. The method of claim 1, furthercomprising the step of rotating the disk and the elastic ribbon about arotating device.
 15. A method of attaching a curved material to asubstrate, comprising the steps of: guiding a first portion of a stripof material onto at least a portion of a periphery of a cam, such that asecond portion of the strip of material folds over a first surface ofthe cam; rotating the cam about a point off-center from a center pointof the cam; and bonding the second portion of the strip of material tothe substrate.
 16. The method of claim 15, wherein the strip of materialcomprises a leg elastic.
 17. The method of claim 15, wherein the stripof material comprises a containment flap.
 18. The method of claim 15,wherein the strip of material comprises a standing leg cuff.
 19. Themethod of claim 15, wherein the cam rotates juxtaposed to the substrate.20. The method of claim 15, wherein the off-center point is at least 0.5centimeter off-center from the center point.
 21. The method of claim 15,wherein the off-center point is at least 1 centimeter off-center fromthe center point.
 22. The method of claim 15, wherein the off-centerpoint is at least 2 centimeters off-center from the center point. 23.The method of claim 15, wherein the off-center point is at least 3centimeters off-center from the center point.
 24. The method of claim15, further comprising the steps of guiding the strip of material onto aslip cut unit and cutting the strip of material.
 25. The method of claim24, wherein a full width of the strip of material is supported on afirst surface of the slip cut unit.
 26. A method of attaching a curvedmaterial to a substrate, comprising the steps of: guiding a strip ofmaterial onto at least a portion of a periphery of a cam; rotating thecam about a point off-center from a center point of the cam; rotatingthe cam and the strip of material with a rotating device toward thesubstrate; and bonding a portion of the strip of material to thesubstrate.
 27. The method of claim 26, wherein the strip of materialcomprises a leg elastic.
 28. The method of claim 26, wherein the stripof material comprises a containment flap.
 29. The method of claim 26,wherein the strip of material comprises a standing leg cuff.
 30. Themethod of claim 26, wherein the off-center point is at least 0.5centimeters off-center from the center point.
 31. The method of claim26, wherein the off-center point is at least 1 centimeter off-centerfrom the center point.
 32. The method of claim 26, wherein theoff-center point is at least 2 centimeters off-center from the centerpoint.
 33. The method of claim 26, wherein the off-center point is atleast 3 centimeters off-center from the center point.
 34. The method ofclaim 26, further comprising the step of ultrasonically bonding theportion of the strip of material to the substrate.
 35. The method ofclaim 26, further comprising the steps of guiding the strip of materialonto a slip cut unit and cutting the strip of material.
 36. The methodof claim 35, wherein a full width of the strip of material is supportedon a first surface of the slip cut unit.